It is critical for a healthy river to have good water quality. However, due to the wide choice of possible water quality parameters which are used, it is difficult to describe and to quantify the water quality of a river. On the other hand, inadequate funding, especially in developing countries, is one of the most common constraints to track all of a river''s water quality parameters, as it is laborious and costly. In view of these facts, Water Quality Indices (WQIs) were one of the most widely used methods worldwide in the successful assessment of river water quality. A WQI is a useful tool for defining the water quality in a water body that can be used by the water authorities for decision-making and operational management. It can also be used to spatially and temporarily compare the water quality of rivers and to provide simple and understandable reports on water quality status to policymakers and the public. Different agencies and researchers have established many WQIs with the goal of developing their own indices or improving existing indices. No single WQI has been approved globally, though. In Pakistan mostly CWQI, NSFWQI is used for testing the water quality but there is no sincere effort was made to introduce the WQIs for assessing the water quality of rivers within the country especially for Indus River which is main source of water in Pakistan. Nonetheless, these two indices are built on the basis of data on specific regions and areas without taking into account the local conditions of Pakistan, such as acceptable parameters in the index that correspond to the conditions of Pakistan and parameter weights considered by major stakeholders. As a result, most variables have been tracked at a single monitoring station, resulting in increased monitoring costs in the field and increased costs of using WQIs. The aim of this study is therefore to frame a new WQI for Indus River, called the Indus River Water Quality Index (INRWQI). This index is specifically designed to address the limitations of the indices currently used, namely the inability to make accurate comparisons of the general status of Indus river water quality, the inability to make these comparisons in a cost-effective manner. INRWQI''s development consists of four steps, which are parameter collection, sub index values collection, scale conversion, weight determination, and generation of final index value by aggregating the sub-indices. In this thesis, the following major investigation is performed to frame the WQIs for assessing the water quality of upper basin of Indus river i.e. origin of Indus River while investigating the various quality parameters 1) Figuring and pointing out the major pollutant and assessable locations at origin of main Indus River, which is Upper Indus Basin (UIB) where the water from six different region combine at one observation point 2) After outlining the quality parameters, establishing the each parameters weight while considering the local conditions/geology and expert’s opinion, which are then used for final index calculation by framing INRWQI with Analytical Hierarchy Process (AHP). 3) Figuring out the minimum number of required parameters and monitoring stations in order to made INRWQI a cost effective way for assessing the water quality of UIB using the multivariate statistical analysis 4) In order to make the water quality assessment more generic and sensitive to allowed the lowest range of each included parameter, a new index is introduced named as “Baluch index” first time by utilizing the concept of graph theory and matrix approach The findings of INRWQI''s implementation for assessing the UIB water quality offered more cost-effective data on the current water quality levels belonging to six regions of UIB and produced a summary of the overall water quality situation in this main Indus river. The latter was possible because INRWQI considered a common set of parameters (representing all aspects of water quality in the rivers), and thus these common parameters can be monitored for all regions of UIB. Furthermore, “Baluch” Index is sensitive to allowed range and reflects the alarming situation when any of the quality parameter from the given is at the higher side of its allowed range. The relevant authorities can use this information obtained from INRWQI and “Baluch” Index to design appropriate programs to improve their water quality management for UIB and main Indus River. Both indices can also be applied to rivers in other provinces of Pakistan and around the world, with some modifications.